The White Star (unmastered)

Your body strains as you summon the might of the White Star. You pull all available moisture from your surroundings forming a singularity in the palm of your hand. While the spell is active, you may use ANOTHER action to send the singularity up to 150ft. When it reaches its destination, the singularity shatters, imploding in on itself, before releasing a perfect ringed nova cutting through all creatures.

All creatures in the radius of the implosion that are size huge or below in a 20ft radius are pulled 10ft towards the center. Then all creature's in the radius must make a CON save against your spell save DC. On a failure the creature takes 6d10 Force damage, and 6d10 Cold damage, and has its movement halved until the end of its next turn, as the sheer cold of the nova freezes their joints and bones. 

On a successful save creatures instead take half damage from both sources, and does not have its movement halved. (the creature is still pulled towards the center).

If the concentration of the spell is broken before the star is projected to another location, the spell fizzles, and the implosion does not occur.